What is PlatformCompare?
PlatformCompare is an independent comparison tool that helps UK investors find the cheapest Stocks & Shares ISA platform for their specific portfolio.
The core product is a fee calculator: enter your portfolio size, account type, and investing style, and we rank every major platform by annual cost in real time.
Why we built it
Platform fees compound in the wrong direction. At 0.45% on a growing portfolio, you’re giving away thousands of pounds over a decade — often without realising it.
Most comparison sites either show incomplete fee data, don’t account for the crossover between fee models, or are sponsored by the platforms they recommend. We wanted to build something genuinely useful: a calculator that does the maths honestly.
How fees are sourced
All fee data is sourced directly from each platform’s published charges pages. We link to the source for every platform. Fees are reviewed and updated regularly — the last update date is shown on each platform page.
We do not take fee data from third parties or rely on estimates. If we can’t verify a fee from the platform’s own website, we don’t include it.
Methodology
The annual fee calculation works as follows:
Platform fee: Calculated based on the fee model:
- Tiered percentage: Each tier of the portfolio is charged at the tier’s rate
- Simple percentage: Portfolio × rate, capped if applicable
- Flat fee: Fixed annual amount regardless of portfolio size
- Zero fee: £0
Dealing fees: Trading cost × number of annual trades, minus any included free trades.
Total: Platform fee + dealing fees, rounded to the nearest pound.
The calculator defaults to ISA, funds, monthly trading (12 trades/year). You can change these to match your situation.
Affiliate disclosure
PlatformCompare is free to use. We may earn a commission when you open an account through our links, at no cost to you.
This does not influence our rankings. Platforms are ranked purely by annual cost for the inputs you provide. The cheapest platform always appears first, regardless of our commercial relationship with them.
Contact
Found an error in our fee data? Let us know.
Last updated: April 2026